1. Field of the Invention
This invention relates to a machine for injecting liquids into materials having the consistency of foodstuffs.
2. Description of the Related Art
U.S. Pat. No. 5,053,237 of Deloy G. Hendricks and Conly L. Hansen provides an apparatus for the needleless injection of injectate into meat.
According to lines 33 through 40 in column 4 of that patent, “[A] nozzle injection apparatus causes the injectate to travel from a reservoir under pressure through a valve and out of a nozzle. Sufficient pressure must be provided such that the injectate can travel completely through the cut of meat, if desired. At the same time, temperature controls must be provided so that the injectate leaves the nozzle at a temperature within a desired temperature range.”
Lines 41 through 48 of column 6 and lines 3 through 26 of column 7 consistently explain:
“ . . . The injection apparatus 10 will, in most cases, include a temperature control feature, such as a water bath 12, for controlling the temperature of the fluid to be injected (“injectate”). The actual injectate fluid will be contained within reservoir 14 disposed within the confines of water bath 12. It is crucial that the temperature be controlled within certain ranges in order to provide for proper injection.
“The apparatus of the present invention also includes a pump 16 and an adjustable relief valve 18 or pressure control assembly. Thus, the injectate can be pumped in a controlled manner from the reservoir through a nozzle assembly 20.
“Also useful in the present apparatus is an electric solenoid valve 22, which may be placed in communication with an adjustable timer to control duration of the bursts of injectate. Thus, the volume of injectate can be carefully controlled as can the amount of injectate which leaves the system. This apparatus can then be connected to a starter and relay to operate the valve 22.
“The injection apparatus will include a nozzle assembly 20. The nozzle assembly will function to direct the injectate in the proper direction and to maintain the stream of injectate at the proper volume. The nozzle assembly 20 may include a plurality of individual nozzles 24.
“The various components of the apparatus are placed in fluid communication by lines including recycle line 26, a feed line 28, and reservoir line 30.
“Finally, the apparatus illustrated in FIG. 9 includes an injection table 32 to provide support for the meat being injected.”
U.S. Pat. No. 6,165,528 of Yoshihiko Tanaka et al. discloses another apparatus for the needleless injection of injectate into meat, which it terms a “pickle injector.” This patent asserts, on line 66 of column 9 through line 8 of column 10:
“The pickle injector of the invention is a device for injecting the liquid substance into the green meat. The pickle injector is provided with a high-pressure liquid generator, a liquid-substance injecting section, and a pressure controller which can control the injection pressure while injecting the liquid substance when the liquid substance is injected from the injecting section to the green meat.”
“The high-pressure liquid generator in the pickle injector the invention may be any mechanism, as long as it can increase the pressure of the liquid substance to a high level . . . ”
No recognition is given in U.S. Pat. No. 6,165,528 is given to the fact that the injectate will be heated by passing through the pump and the pressure controller; nor is there any discussion concerning reclaiming injectate that does not find its way into the meat.
The apparatus of U.S. Pat. No. 6,165,528 does, however, preferably employ a manifold, as described in line 33 through 60 of column 10:
“ . . . the high-pressure liquid substance is transferred from the high-pressure liquid generator via the high-pressure piping to the injecting section, and it is preferable to use the injecting section which has a member called a manifold for branching a single flow from the high-pressure piping to plural flows. The manifold is preferably placed on the tip end of the injecting section, but can be placed midway in the piping as the case may be.
“The injecting section of the conventional high-pressure liquid generator is of a single-hole type or has a form in which the piping in the manifold is branched radially. The present inventors have manufactured a manifold especially suitable for a pickle injector for meat, piping in the manifold is branched and the branched pipes are parallelly arranged. Here, the parallel arrangement includes not only the arrangement where the pipes are arranged parallel in a row but also the arrangement where the pipes are arranged zigzag or parallel in multiple rows. By arranging nozzles parallel, a nozzle interval can be narrowed to 10 mm or less, e.g., 5.6 mm for injection. Therefore, a highly dense and uniform injection is feasible. Further preferably used is a manifold which has multiple coherent stream injection nozzles arranged parallel in this manner.
“When the manifold is used, the high-pressure liquid substance is injected as the coherent stream from the nozzle on the tip end of each piping. The liquid substance is injected simultaneously from the parallel arranged nozzles to the green meat . . . . ”
Subsequently, U.S. Pat. No. 6,165,528 explains, in lines 44 through 47 of column 17, “The liquid substance is injected as a coherent stream from the tip end of the injection nozzle of the manifold 7 in contact with the green meat.” Thus, the nozzle actually touches the meat, creating an increased risk of contamination.
In lines 42 through 45 of column 18, similar language describes another embodiment. Also for this other embodiment, however, lines 34 through line 36 of column 18 indicate, “The manifold 7 is . . . lowered from above to hit against the green meat.”
Although in lines 10 through 11 of column 17 and in line 16 of column 18, U.S. Pat. No. 6,165,528 states that high-pressure piping 6 is “constituted of a flexible hose,” no purpose is given for this flexibility. Thus, it is logical to assume that the flexibility is for the traditional purpose in high-pressure lines, viz., absorbing forces associated with the pressure that could damage a more rigid line.
Finally, in its Description of the Related Art, U.S. Pat. No. 6,165,528 provides a summary of needleless injectors and related devices.
To the best of the inventors' knowledge, all previous needleless injectors have utilized pumps, such as positive displacement pumps, which must run continuously in order to maintain the fluid to be used as an injectate under constant high pressure. Heat generated by such continuous operation is transferred to the injectate as it passes through the pump.
Moreover, in the practical implementation of U.S. Pat. No. 5,053,237, once the pressure in the system reached the desired level, a pressure relief valve 18 would prevent the continuously running pump 16 from further raising the pressure. This was accomplished by allowing the injectate to flow from the pump 16, through the pressure relief valve 18, and back to the reservoir 14 that supplied the pump 16 with injectate. A solenoid valve 22 allowed the injectate to flow to the nozzles 24 of the nozzle assembly 20 when desired. The re-circulation of the injectate through the continuously running pump 16 tended to raise the temperature of the injectate even more.
Not only is a cooling system necessary to keep the injectate within the required temperature range, but the added volume in plumbing necessary to provide the recycling and the additional capacity within the reservoir 14 to account for the injectate that is being cooled within the water bath 12 requires a greater quantity of injectate than would otherwise be necessary. This, in turn, mandated the use of a larger pump 16. More energy was required both because of the larger capacity of the pump 16 and because of the continuous operation. And since injectate is purged when it is desired to use another fluid as the injectate, the cost of injectate was higher.
Further, there is an interest in a needleless injection apparatus that can inject a liquid into a subject with minimal damage to the subject itself. There is also an interest in a needleless injection apparatus that can be easily maintained and cleaned in accordance with applicable governmental food safety standards. In addition, there is a need for a needleless injection apparatus that is capable of operation within an existing continuous food preparation/production manufacturing facility without a significant investment in additional equipment and without significant modification of an existing manufacturing process.
Accordingly, reducing exposure of machine components to moisture in the production environment is required to minimize maintenance of the machine. Further, minimizing exposure of the threading on key machine components to the injection fluid or a cleaning solution is required to enhance longevity of the machine and to reduce possible contamination of the injection subjects.
In addition, operation in a continuous environment requires immediate reaction to subtle changes in production process variables. For example, an injection spray that is substantially uniform, without any hesitation during or between injection bursts is required. Accordingly, a method to ensure steady and consistent injection bursts is needed. In addition, the ability to automatically refresh the fluid supply is also desirable.